On Wed, Jul 15, 2015 at 12:03:45AM -0400, Ted Unangst wrote: > Tobias Ulmer wrote: > > As we all know, some Thinkpads have problems with their EC fan control. > > EC is not spinning up the fans to maximum speed, let alone blast mode. > > They also do not offer ACPI methods to spin the fan up. > > > > Previous diffs doing manual fan control were always rejected because > > hooking into the sensors framework with fixed temp limits is crude and > > there are concerns with slowing the fan down and frying the hardware. > > > > This is an attempt to solve the problem slightly differently. > > - Hook into acpitz and only speed the fan up when it is requesting active > > cooling > > - Never set the fan to a mode that would endanger the hardware should we > > crash > > Can you clarify what if any effect should be observed with this diff? Will it > make my fans louder or quieter? > > (I was very happy to discover that with the C states diff, my one thinkpad now > idles at 3000 rpm vs 3500 rpm, and that is actually a lot quieter.) >
There should be zero change in behaviour for normal use. Only if thermal zone temp reaches its "passive" cooling limit (93C on my X201) and demands active cooling will it spin the fan up. At the same time acpitz also reduces cpuspeed. Once temps are back to normal it switches to automatic mode and the fans should quiet down.
